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RE: Lightening and mast mounted preamps



Steve,
Take a look at the picture, "Old antenna" on the site
(www.wmfd.com/w8gsm). I used a G-5500 Az/El rotor which took care of all
the antennas. You'll see a bracket I had made, which allowed the 1.2m
dish to startle the rotors. One word of caution: The wind loading of the
dish did contribute to kissing off an elevation motor. The load is large
and requires parking the dish horizontally so the wind spills out. One
day I was doing AO40 telm gathering and left the system un-attended. Got
45 mPH winds, the motor tried to maintain elevation, and lost out to
mother nature... Also, drill a couple holes in the dish so the rain can
drain out... I eventually abandon this arrangement and went with a 7.5
footer driven with a W0LMD motor system..
I will say that the 1.2m dish did a wonderful job...

-----Original Message-----
From: Steve Egert [mailto:segert@adelphia.net] 
Sent: Sunday, March 09, 2003 9:27 PM
To: Gunther Meisse
Subject: Re: [amsat-bb] Lightening and mast mounted preamps


Gunther,
I saw you're website and thanks for posting the drawing of the channel
master dish.  I just found one in a junk pile and am in the process of
putting it up.  Tell me, what did you use for an elevation rotor?

Thanks,
Steve -- K6UX

----- Original Message -----
From: "Gunther Meisse" <gjmouse@neo.rr.com>
To: <amsat-bb@AMSAT.Org>
Sent: Saturday, March 08, 2003 3:24 PM
Subject: RE: [amsat-bb] Lightening and mast mounted preamps


> Just a thought:
> After MANY 2Ghz lightning problems at work, I have modified my shack 
> so that all feed  lines going to my antenna farm are run through RF 
> relays with the normally closed (Power off) side dead shorted to my 
> station ground system. ( 4 - 6' copper clad ground rods spaced 6 feet 
> apart.) The best way to protect everything. If interested in details 
> see dia on www.wmfd.com/w8gsm 73
> Gunther W8GSM
>
>
> -----Original Message-----
> From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org] On 
> Behalf Of kevin schuchmann
> Sent: Saturday, March 08, 2003 5:54 PM
> To: amsat-bb@AMSAT.Org; John Geiger
> Subject: Re: [amsat-bb] Lightening and mast mounted preamps
>
>
> Hello John,
>    guess it would depend on the type of preamp, but Icom ones for 
> example are out of the RF path when not powered, so if the rig is off 
> or the preamp is turned off they are relatively safe... would think 
> most preamps operate the same way... a near miss would have to induce 
> a high enough voltage to jump the relay contact points inside the 
> preamp... 73's Kevin WA6FWF
>
> ----- Original Message -----
> From: "John Geiger" <johngeig@yahoo.com>
> To: <sidewindersontwo@yahoogroups.com>; <amsat-bb@AMSAT.Org>; 
> <vhf@w6yx.stanford.edu>; <newsvhf@mailman.qth.net>; 
> <nwwsvhf@mailman.qth.net>
> Sent: Saturday, March 08, 2003 1:55 PM
> Subject: [amsat-bb] Lightening and mast mounted preamps
>
>
> > I have a question that I have not seen addressed
> > before.  Asked my friend Don, NL7CO, who is a big VHF operator, and 
> > he
>
> > didn't know but said put it on the reflector, so here it is.
> >
> > We generally unhook our antennas during thunderstorms because a 
> > nearby lightening strike can cause enough energy to burn out the 
> > receiver's front end-or at least important components in the front 
> > end, like the RF amp.  What happens with mast mounted preamps?  You
> > usually cannot unhook the coax from them during a thunderstorm.  Do
> > they have some sort of protection device built in to handle surges
> > down the coax?
> >
> > WOuld be interested to know, as we get pretty good thunderstorms 
> > around here.
> >
> > 73s john NE0P  EM04to-Lawton, OK
> >
> > __________________________________________________
> > Do you Yahoo!?
> > Yahoo! Tax Center - forms, calculators, tips, more 
> > http://taxes.yahoo.com/
> > ----
> > Sent via amsat-bb@amsat.org. Opinions expressed are those of the 
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> >
>
>
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the 
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> ----
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